Incoming fan for more makeup air?

[mjwalsh]

Has anyone tried using a fan to increase the flow of air into their laundromat as needed for make up air for dryer stacks etc?

[Andy]

my old boiler used to have such a system, a small sail switch in the opening turned the fans on/off

[alesser738]

I'd really appreciate if anyone has used fans or some other sytem to get makeup air to the dryers. I'm building a mat with 8 80 lb dryers and 24 stacks with very little makeup air potential other then somesort of fan system.
I don't think people realize how important makeup really is. I added probably just 15 sq feet more makeup air to my mat which only has 24 stacks and saved almost $500 in one months gas bill (therm use was almost identical/price also).
Has anyone used a fan sytem?
I'm more interested in something fancier then just a fan though if anyone has used it. thanks

[fluffy]

The $500 savings doesn't make any sense - did you check the bill dates (does it cover the number of days?). If you are using the same therms and the same price, the bill is the same.

[anonymous]

Fluffy, it is probably off but it is possible. If the dryers were so starved for air that they were not completely burning the gas then adding more air could reduce the gas consumption needed to generate the same amount of heat.

As for using a fan, it is done all the time on industrial boilers. To do it right you need more than just a fan -- you need some sort of pressure measuring system that will control how much air the fan forces in based on how many dryers are running. You don't want to create a large positive pressure behind the dryers or you will have other problems with your dryer flames.

[Anonymous]

i agree with cleanclothes i think the dryers were not burning right because they did not have enough air. i have the same problem with makeup air. my landlord won't let me put holes in the roof. i'm going to look at new dryers next week that use less gas and less air and will hopefully work right in my location.

[The wizard]

THE CORRECT AMOUNT OF MAKE-UP AIR IS CRITICAL TO MAINTAIN EFFICIENCY OF YOUR ENTIRE LAUNDROMAT. Many Laundromats I encounter are usually lacking proper make up air. The results to dryer efficiency are obvious. However, one area most people do not see is the dryers will pull air from where ever available. Therefore, your hvac system works over time conditioning fresh air being pulled into your laundry. If you can walk in the door and notice air being pulled in you have a big problem. Having a neutral balance is ideal but hard to accomplish. You want to keep the makeup air behind the dryers and the conditioned air for your customers. They do make variable speed fans which operate on a transducer which monitor air pressure measure in inches of w.c. “water column.” These I feel are not excessive in cost but over time your gas and hvac saving will more then pay for the “invisible thief.” The other thief is lint build up on yours dryers, hot water heater, hvac coils.

[mjwalsh]

I agree with "The "Wizard" 100%. It would great if someone who actually uses such a system would share their experience & how much cost is actually involved for the transducer & fan portion. It also would be nice to go further & actually get some brands & part numbers listed. Having boilers etc that bring make up air into sealed pipes that need zero make up air from existing vents is definitely a factor too.